Minimally Invasive Two-Dimensional Grid Electrode

ABSTRACT

A system for deploying an electrode array at a target location through a hole formed in the patient&#39;s cranium. The system includes an array of electrodes attached to a substrate and an inserter attached to the substrate and/or the array of electrodes. The inserter, substrate and array of electrodes are configured into a first compressed state and are positioned within the lumen of a cannula. Using the cannula, the system is inserted through the hole, the cannula is then removed, and the inserter is used to transition the substrate and electrode array from the first compressed state to a second uncompressed state, thereby deploying the array of electrodes at the target location.

CROSS-REFERENCE

The present application relies on U.S. Patent Provisional ApplicationNo. 62/732,654, filed on Sep. 18, 2018 and entitled “Minimally InvasiveTwo-Dimensional Grid Electrode”, and U.S. Patent Provisional ApplicationNo. 62/767,504, filed on Nov. 14, 2018 and entitled “Method and Systemfor Electrode Verification”, for priority, both of which areincorporated herein by reference.

FIELD

The present specification is related generally to the field ofelectrodes. More specifically, the present specification is related to acompressible multi-contact electrode that can be inserted through anaccess hole via a surgical procedure, expanded to its full dimensions,verified as to position and location prior to completion of the surgicalprocedure, and preferably extracted via the same access hole.

BACKGROUND

Surgical treatment for epilepsy is being utilized more often when drugmedical therapy fails to control the disease. Evaluation prior tosurgery involves conducting direct brain recordings to verify that theepileptic focus is treatable. This type of evaluation is well understoodby those of ordinary skill in the art.

Typically, hundreds of electrodes are needed to thoroughly map thebrain. The electrodes employed may be in arrays, for example an 8×8array with 64 contacts. To implant these electrode arrays, a section ofskull is removed (skull flap) to allow placement of the electrodes, asshown in FIG. 1. Referring to FIG. 1, the electrodes are in a grid array100 and are typically thin and flexible. Some electrodes or a portion ofthe electrode array 100 will be placed at the location of the skullflap, and other electrodes will be tucked between the skull and thebrain over surfaces that are not directly exposed. To remove theelectrode arrays, another surgical procedure is needed. The risks, costsand discomfort for these procedures are significant.

Other electrodes employed may be strip electrodes or needle-like depthelectrodes. Strip electrodes may be inserted radially through burrholes, which are typically on the order of 2 cm in diameter. Depthelectrodes may be inserted through small drill holes in the skull andremoved without anesthesia.

Further, the placement of electrodes is important for interpretingelectrode signals that are generated. The desired electrode locationsare usually well defined and may be on the surface of the scalp, in oron the brain, or at some other location on the body. Depth electrodesand grid electrodes consist of multiple electrodes in a matrix, wherethe expected geometric relation of each input to all other inputs withinthe matrix is known. In complex cases with multiple grids or multipledepth electrodes, the locations of each individual or group ofelectrodes is either part of the surgical planning or is noted duringthe surgery. A placement error will lead to either confusion because thetesting results do not make sense or worse—a mistaken conclusion thatcan affect treatment and outcome.

What is needed is a compressible grid electrode that can be compressed,folded, or otherwise modified in shape to allow for insertion and thatis configured to subsequently unfolded when in the proper location. Whatis also needed is a folding grid electrode that is configured to beinserted into a relatively small access hole that can be expanded to itsfull dimension, that can be verified as to position and location priorto completion of the surgical procedure, and that can be extracted viathe same access hole.

SUMMARY

The following embodiments and aspects thereof are described andillustrated in conjunction with systems, tools and methods, which aremeant to be exemplary and illustrative, and not limiting in scope. Thepresent application discloses numerous embodiments.

The present specification discloses a system for deploying an electrodearray at a target location within a patient's cranium through a holeformed in the patient's cranium, the system comprising: a substrate; anarray of electrodes attached to the substrate; an inserter attached tothe substrate, wherein the inserter, the substrate, and the array ofelectrodes are configured in a first compressed state and wherein theinserter is configured to expand from the first compressed state to asecond uncompressed state; and a cannula configured to accommodate theinserter, the substrate and the array of electrodes in the firstcompressed state and configured to release the inserter, the substrateand the array of electrodes through the hole and within the patient'scranium at the target location.

Optionally, in the first compressed state, the substrate and array ofelectrodes have a width that is less than a width of the substrate andarray of electrodes in the second uncompressed state.

Optionally, the array of electrodes comprises a plurality of contactshaving associated lead wires, and wherein each of said lead wires areconnected to a terminal on an electrical device.

Optionally, the system further comprises an actuator coupled to theinserter. Optionally, the actuator is configured to be accessibleoutside the patient's cranium and further configured such that, when aforce is applied to the actuator, in a first direction, the inserterexpands, thereby causing the inserter, the substrate, and the array ofelectrodes to be in the second uncompressed state. Optionally, theactuator is configured to be accessible outside the patient's craniumand further configured such that, when a force is applied to theactuator, in a second direction, the inserter compresses, therebycausing the inserter, the substrate, and the array of electrodes to bein the first compressed state.

Optionally, the inserter comprises at least a first spring element and asecond spring element, wherein a distal end of the first spring elementis attached to a first edge of the substrate, wherein a distal end ofthe second spring element is attached to a second edge of the substrate,and wherein the first edge opposes the second edge. Optionally, aproximal end of the first spring element and a proximal end of thesecond spring element are connected to a common member.

Optionally, the inserter comprises a multi-segmented cantilever coupledto a first and a second actuator. Optionally, the multi-segmentedcantilever is configured to expand when the first actuator is pulled ina first direction and the second actuator is pushed in an opposingsecond direction.

Optionally, the substrate has a tapered proximal portion configured tofacilitate ease of extraction of the substrate through the hole.

Optionally, the cannula includes a mark to facilitate a properorientation of a contact surface of the array of electrodes duringrelease of the inserter, the substrate and the array of electrodes.

Optionally, the cannula has an ovoid cross-section and is curved alongits length.

Optionally, the cannula includes a port configured to provide compressedgas to generate a brain-cranium gap for inserting the cannula throughthe hole.

Optionally, the cannula further accommodates a front-pointing viewingelement and at least one illuminator.

The present specification also discloses a method of deploying anelectrode array at a target location within a patient's cranium througha hole formed in the patient's cranium, the method comprising: obtainingan electrode array system, wherein the electrode array system comprisesa cannula having a lumen, a substrate, an array of electrodes attachedto the substrate, and an inserter attached to the substrate, wherein thesubstrate, the array of electrodes, and the inserter are positioned inthe lumen in a first compressed state; inserting the cannula through thehole; sliding the cannula backwards while positioning the inserter, thesubstrate, and the array of electrodes at the target location; andcausing the inserter, the substrate and the array of electrodes totransition from the first compressed state to a second uncompressedstate at the target location.

Optionally, in the first compressed state, the substrate and array ofelectrodes have a width that is less than a width of the substrate andthe array of electrodes in the second uncompressed state.

Optionally, the array of electrodes comprises a plurality of contactshaving associated lead wires and wherein each of said lead wires areconnected to a terminal on an electrical device.

Optionally, the method further comprises causing the inserter, thesubstrate and the array of electrodes to transition from the firstcompressed state to the second uncompressed state by moving an actuatorattached to the inserter. Optionally, the actuator is configured to beaccessible outside the patient's cranium and further configured suchthat, when a force is applied to the actuator, in a first direction, theinserter expands, thereby causing the inserter, the substrate, and thearray of electrodes to be in the second uncompressed state. Optionally,the actuator is configured to be accessible outside the patient'scranium and further configured such that, when a force is applied to theactuator, in a second direction, the inserter compresses, therebycausing the inserter, the substrate, and the array of electrodes to bein the first compressed state.

Optionally, the inserter comprises at least a first spring element and asecond spring element, wherein a distal end of the first spring elementis attached to a first edge of the substrate, wherein a distal end ofthe second spring element is attached to a second edge of the substrate,and wherein the first edge opposes the second edge. Optionally, aproximal end of the first spring element and a proximal end of thesecond spring element are connected to a common member.

Optionally, the inserter comprises a multi-segmented cantilever coupledto an actuator. Optionally, the multi-segmented cantilever is configuredto expand when the actuator is pulled in a first direction andconfigured to contract when the actuator is pulled in a seconddirection.

Optionally, the method further comprises causing the inserter, thesubstrate and the array of electrodes to transition from the seconduncompressed state to the first uncompressed state at the targetlocation. Optionally, the inserter, the substrate and the array ofelectrodes transitions from the second uncompressed state to the firstuncompressed state by moving an actuator in physical communication withthe inserter. Optionally, the method further comprises removing thecannula and the inserter through the hole. Optionally, the methodfurther comprises extracting the array of electrodes through the hole.

Optionally, the method further comprises verifying a physical positionof at least one of the inserter, the substrate or the array ofelectrodes within the patient's cranium.

The present specification also discloses a method of deploying anelectrode array at a target location onto a patient's cortex through aburr hole formed on the patient's cranium, the method comprising:inserting a cannula through said burr hole, said cannula accommodatingan inserter and an array of electrodes, wherein said inserter and arrayof electrodes are in a first state; sliding the cannula backwards whilepositioning said inserter and array of electrodes in said first state atsaid target location; causing said array of electrodes to be in a secondstate at said target location; and verifying said positioning of saidinserter and array of electrodes at said target location.

Optionally, the method further comprises removing the cannula and theinserter through the burr hole. Optionally, the method further comprisesextracting the array of electrodes through the burr hole.

Optionally, in said first state, the inserter and array of electrodesare compressed.

Optionally, in said second state, the array of electrodes is expanded.

The present specification also discloses a system for deploying anelectrode array at a target location onto a patient's cortex through aburr hole formed on the patient's cranium, the system comprising: anarray of electrodes formed on a substrate; an inserter attached to thearray of electrodes, wherein the inserter and array of electrodes areconfigured into a first state; and a cannula, wherein the cannulaaccommodates the inserter and array of electrodes in said first state,and wherein the cannula is inserted through the burr hole to deploy thearray of electrodes at the target location in a second state.

Optionally, in said first state, the inserter and array of electrodesare compressed.

Optionally, in said second state, the array of electrodes is expanded.

Optionally, the array of electrodes comprises a plurality of contactshaving associated lead wires, wherein said lead wires are bundled intoat least one pigtail.

Optionally, an actuator is coupled to the inserter. Optionally,application of a force on the actuator in a direction causes theinserter to be expanded, thereby causing the array of electrodes to bein said second state.

Optionally, the cannula and the inserter are removed from the burr holeafter the array of electrodes is deployed in said second state.

Optionally, the array of electrodes is removed through the burr holeusing said at least one pigtail.

Optionally, the inserter comprises a multi-segmented cantilever coupledto an actuator.

The present specification also discloses a method of deploying anelectrode array at a target location onto a patient's cortex through aburr hole formed on the patient's cranium, the method comprising:inserting a cannula through said burr hole, said cannula accommodatingan inserter and an array of electrodes, wherein said inserter and arrayof electrodes are in a first state; and sliding the cannula backwardswhile positioning said inserter and array of electrodes in said firststate at said target location.

Optionally, the method further comprises causing said inserter and arrayof electrodes to be in a second state at said target location.

Optionally, said second state is caused by activating an actuatorcoupled to said inserter.

Optionally, the method further comprises verifying said positioning ofsaid inserter and array of electrodes at said target location.

Optionally, the method further comprises removing the cannula and theinserter through the burr hole.

Optionally, the method further comprises extracting the array ofelectrodes through the burr hole.

The present specification also discloses a method of deploying anelectrode array at a target location onto a patient's cortex through aburr hole formed on the patient's cranium, the method comprising:inserting a cannula through said burr hole, said cannula accommodatingan inserter and an array of electrodes, wherein said inserter and arrayof electrodes are in a first state; sliding the cannula backwards whilepositioning said inserter and array of electrodes in said first state atsaid target location; causing said array of electrodes to be in a secondstate at said target location; and verifying said positioning of saidinserter and array of electrodes at said target location.

Optionally, the method further comprises removing the cannula and theinserter through the burr hole.

Optionally, the method further comprises extracting the array ofelectrodes through the burr hole.

Optionally, in said first state, the inserter and array of electrodesare compressed.

Optionally, in said second state, the array of electrodes is expanded.

The aforementioned and other embodiments of the present shall bedescribed in greater depth in the drawings and detailed descriptionprovided below.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present specificationwill be further appreciated, as they become better understood byreference to the following detailed description when considered inconnection with the accompanying drawings:

FIG. 1 is an illustration of a conventional technique for applying gridelectrodes;

FIG. 2A is an illustration of an electrode system, in compressed formand housed in a cannula, in accordance with some embodiments of thepresent specification;

FIG. 2B is an illustration of an electrode system, in compressed formand removed from a cannula, in accordance with some embodiments of thepresent specification;

FIG. 2C is an illustration of the electrode system of FIGS. 2A and 2B,in uncompressed or expanded form, in accordance with some embodiments ofthe present specification;

FIG. 2D shows an inserter configured in the form of a scissors jackmechanism, in accordance with some embodiments of the presentspecification;

FIG. 3 is a flow chart describing exemplary steps for inserting,expanding, verifying, and extracting the electrode system, in accordancewith some embodiments of the present specification;

FIG. 4 illustrates exemplary steps for inserting the electrode systeminto a burr hole, in accordance with some embodiments of the presentspecification;

FIG. 5 illustrates exemplary steps for verifying electrode placementusing excitation and field measurements, in accordance with someembodiments of the present specification;

FIG. 6A illustrates an assembly of an electrode system in compressedform and housed in a cannula along with a visualization or imagingsystem, in accordance with some embodiments of the presentspecification;

FIG. 6B is an illustration of the electrode system of FIG. 6A incompressed form and removed from the cannula, in accordance with someembodiments of the present specification;

FIG. 6C is an illustration of the electrode system of FIGS. 6A and 6B,in uncompressed or expanded form, in accordance with some embodiments ofthe present specification;

FIG. 6D illustrates the visualization or imaging system protrudingbeyond a distal end of the cannula, in accordance with some embodimentsof the present specification;

FIG. 6E illustrates a first cannula with a port and a second cannulawith an oblong/ovoid cross-section and a curved length, in accordancewith some embodiments of the present specification;

FIG. 7 shows first, second and third configurations of a springfunctioning as an inserter, in accordance with some embodiments of thepresent specification; and,

FIG. 8 is a workflow describing exemplary steps for inserting,expanding, verifying, and extracting the electrode system of FIG. 6A, inaccordance with some embodiments of the present specification.

DETAILED DESCRIPTION

The term ‘user’ is used interchangeably to refer to a surgeon,neuro-physician, neuro-surgeon, neuro-physiologist, technician oroperator of an electroencephalogram or electroencephalography (EEG)system and/or other patient-care personnel or staff.

A “computing device” is at least one of a cellular phone, PDA, smartphone, tablet computing device, patient monitor, custom kiosk, or othercomputing device configured to execute programmatic instructions. Itshould further be appreciated that each device and monitoring system mayhave wireless and wired receivers and transmitters capable of sendingand transmitting data. Each “computing device” may be coupled to atleast one display, which displays information about the patientparameters and the functioning of the system, by means of a graphicaluser interface (GUI). The GUI also presents various menus that allowusers to configure settings according to their requirements. The systemfurther comprises at least one processor to control the operation of theentire system and its components. It should further be appreciated thatthe at least one processor is capable of processing programmaticinstructions, has a memory capable of storing programmatic instructions,and employs software comprised of a plurality of programmaticinstructions for performing the processes described herein. In oneembodiment, the at least one processor is a computing device capable ofreceiving, executing, and transmitting a plurality of programmaticinstructions stored on a volatile or non-volatile computer readablemedium. In addition, the software comprised of a plurality ofprogrammatic instructions for performing the processes described hereinmay be implemented by a computer processor capable of processingprogrammatic instructions and a memory capable of storing programmaticinstructions.

“Electrode” refers to a conductor used to establish electrical contactwith a nonmetallic part of a circuit. EEG electrodes are small metaldiscs usually made of stainless steel, tin, gold or silver covered witha silver chloride coating. They are typically placed on the scalp onpredetermined locations. “Depth electrodes” are made of thin wires, areconfigured to record seizures which may start deep in the brain, and aretypically inserted into the brain parenchyma. “Strip and gridelectrodes” are conductors that are positioned, implanted or embeddedwithin a thin sheet of plastic and are typically configured to be placedon a surface of the brain.

The present specification is directed towards multiple embodiments. Thefollowing disclosure is provided in order to enable a person havingordinary skill in the art to practice the invention. Language used inthis specification should not be interpreted as a general disavowal ofany one specific embodiment or used to limit the claims beyond themeaning of the terms used therein. The general principles defined hereinmay be applied to other embodiments and applications without departingfrom the spirit and scope of the invention. Also, the terminology andphraseology used is for the purpose of describing exemplary embodimentsand should not be considered limiting. Thus, the present invention is tobe accorded the widest scope encompassing numerous alternatives,modifications and equivalents consistent with the principles andfeatures disclosed. For purpose of clarity, details relating totechnical material that is known in the technical fields related to theinvention have not been described in detail so as not to unnecessarilyobscure the present invention.

In the description and claims of the application, each of the words“comprise” “include” and “have”, and forms thereof, are not necessarilylimited to members in a list with which the words may be associated. Itshould be noted herein that any feature or component described inassociation with a specific embodiment may be used and implemented withany other embodiment unless clearly indicated otherwise.

As used herein, the indefinite articles “a” and “an” mean “at least one”or “one or more” unless the context clearly dictates otherwise.

The present specification is directed towards electrodes and inserters,together referred to as an “electrode system”, configured to allow forinsertion of a compressible grid electrode, in a compressedconfiguration, through a relatively small hole, which can then beexpanded to position an array of contacts over the surface of the brain.In some embodiments, the hole is dime-sized. In some embodiments, adiameter of the hole ranges between 2 mm and 30 mm, preferably 10 mm to20 mm, and any numerical increment therein. The system can then use anelectrode location system to verify that the grid electrode is properlypositioned during the surgery. The grid electrode may be removed withoutadditional surgery in an antiseptic environment.

FIG. 2A illustrates an assembly of an electrode system 200, withelectrode array 202 in compressed form and housed in a cannula 204, inaccordance with some embodiments of the present specification. Theelectrode system 200 comprises an inserter 201 attached to the electrodearray 202. The electrode system 200 is in compressed form and containedwithin the cannula 204, wherein the cannula 204 is stiff enough to beinserted into a desired location and depth of a patient's skull orcranium. In embodiments, the electrode array 202 comprises a distal end202 a and a proximal end 202 b.

In an embodiment, the electrode array 202 is a grid electrode andconsists of an array of contacts 203, each of which has a lead wire 207(visible in FIG. 2C). The lead wires 207 are bundled into one or morepigtails 208 and terminated in a multi-contact connector. A pigtail isdefined as a short length of wire that connects, at one end, to aterminal on an electrical or computing device and, at the other end tocircuit wires. Within or alongside the compressed electrode array 202 isa guide wire 206. In an alternate configuration, a plunger may followthe lead wires 207 to the proximal end 202 b of the compressed electrodearray 202. Operationally, after the cannula 204 has been inserted into apatient's skull, the cannula is pulled back to thereby release thecompressed electrode array 202 at the desired location. The guide wire206 or the plunger is then used to keep the electrode array 202 at thedesired location and depth. The electrode system 200 also includes, insome embodiments, an actuator 210 described in greater detail below.

FIG. 2B is an illustration of the electrode system 200 of FIG. 2A, withelectrode array 202 in compressed form and removed from the cannula 204,in accordance with some embodiments of the present specification. Theelectrode array 202 is shown in a compressed configuration with thearray of contacts 203 and the lead wires (or electrode leads) 207bundled into at least one pigtail 208. The electrode leads are flexibleand resist breakage when the electrode array 202 is compressed anduncompressed.

In embodiments, the electrode array 202 is attached or coupled to asubstrate 220 having length and/or width dimensions of 2 cm to 15 cm inan uncompressed form. The substrate 220 of the electrode array 202 is ofsufficient strength and flexibility so that the array 202 will notfragment during insertion or removal. In some embodiments, if necessary,reinforcing filaments can be added to the substrate which willeffectively distribute the forces that come into play during compressionand release of the electrode array 202. In embodiments, the substrate isbiocompatible for temporary implantation and can be sterilized. Invarious embodiments, the substrate 220 is made of flexible biocompatiblematerial such as silicone rubber and with conductive contacts as arecurrently used for grid electrodes such as stainless steel, platinum orcarbon. The geometry can be variable both in size and shape as iscurrently supported by invasively placed cortical grid electrodes. Thecontacts may also be placed asymmetrically to accommodate optimal springpositions and to allow ease of placement and removal.

In various embodiments, the electrode array 202 is compressed into aplurality of configurations such as, but not limited to, a firstconfiguration wherein the array 202 is rolled up, a second configurationwherein the array 202 is folded in an accordion-like manner, a thirdconfiguration wherein the array 202 is compressed in a serpentinemanner, a fourth configuration wherein the array 202 is squeezed in atube-like manner or in other ways or configurations that combine or aredifferent from these four exemplary configurations.

Also shown in FIG. 2B is the inserter 201 in compressed form along withan actuator 210. A compressed assembly 200 a of the inserter 201 and theelectrode array 202 is also shown. In the compressed form, the inserter201 has dimensions of 2 cm to 15 cm long and less than 1 cm in width. Invarious embodiments, the inserter 201 is attached or coupled to theelectrode array 202 and/or the substrate 220 using any attachment meansknown in the art. In some embodiments, in a compressed state, thesubstrate 220, in combination with the electrodes/contacts 203, theinserter 201 and the lead wires 207, have dimensions that are less thanthe dimensions of the substrate, electrode/contacts, and lead wires inan uncompressed state.

FIG. 2C is an illustration of the electrode system 200 of FIGS. 2A and2B, in uncompressed or expanded form, in accordance with someembodiments of the present specification. As described earlier, the gridelectrode array 202 consists of an array of contacts 203, each of whichhas a lead wire 207. The lead wires 207 are bundled into one or morepigtails 208 and terminated in a multi-contact connector. The pigtails208 pass through the patient's skull and skin and the connector isexternal to the patient. In some embodiments, the grid electrode array202 may be fabricated on the substrate 220 which is thin and flexibleand which conforms to the surface of the patient's brain when applied,and which can be compressed or folded into a tube-like structure forinsertion.

An uncompressed or unfurled configuration 200 b of the inserter 201 andthe electrode array 202 is also shown. The unfurling of the electrodearray 202 requires it to roll across or slide across the surface of thepatient's brain. In embodiments, this is accomplished in a plurality ofways depending on the compression method and the shape or configurationof the final compressed grid array 202. In various embodiments, ascissors action, a fluid filled hydraulic system built into the gridarray 202, a multi-segmented cantilevered action, or a spring which isgradually released as the cannula 204 is retracted is used to accomplishthe unfurling. In other embodiments, the grid 202 comprises ashape-memory material that expands once the cannula 204 is retractedfrom the compressed assembly of the electrode array 202 and inserter201. In some embodiments, a combination of these unfurling systems isused.

The inserter 201 is also shown in uncompressed form in the FIG. 2C,which employs a mechanical actuator 210 to unfurl the compressedelectrode system 200 a (shown in FIG. 2B) into an uncompressed state 200b for placement on the surface of a patient's brain, in accordance withsome embodiments of the present specification. In some embodiments, asshown in FIG. 2C, the actuator 210 is coupled to a collapsible as wellas expandable structure 211 (for example, a multi-segmented cantilever).In some embodiments, a force applied on the actuator 210 in a firstdirection causes the structure 211 to expand (thereby causing theattached electrode array 202 to also unfurl) while a force applied onthe actuator 210 in a second direction (opposite to the first direction)causes the structure 211 to collapse or compress.

FIG. 2D shows an exemplary inserter 201 d configured in the form of amulti-segmented cantilever or scissors jack mechanism, in accordancewith some embodiments of the present specification. Configuration 265shows the inserter 201 d in a fully compressed state, configuration 267shows the inserter 201 d in a partially expanded state whileconfiguration 269 shows the inserter 201 d in a fully expanded state.The scissors jack mechanism of the inserter 201 d comprises a pluralityof segments 250 coupled together via a plurality of hinges 252 thatallow flexible expansion or compression of the segments 250. First andsecond sliding joints 254, 255 enable portions of the coupled segments250 to slide up or down along first and second bars 257, 258 duringexpansion or compression of the segments 250, respectively. The inserter201 d also comprises a proximal actuator 260 and a distal actuator 262to enable modulation of the inserter 201 d into expanded or compressedstates. During operation, a user pulls the distal actuator 262 down (orholds stationary) and pushes the proximal actuator 260 up therebyapplying opposing forces to the proximal and distal hinges 252 andexpanding the scissors jack mechanism laterally.

FIG. 3 is a flow chart describing exemplary steps for inserting,expanding, verifying, and extracting the electrode system, in accordancewith some embodiments of the present specification. At step 305, aninsertion, access or burr hole is formed or created in a patient's skullor cranium at a desired location and of a desired depth so as to enableaccess to a surface of the patient's brain or cortex. At step 310, anassembly of an inserter attached to an electrode array is compressed andslid or inserted into the access or burr hole through a cannula. At step315, the cannula is slid back leaving the compressed assembly of theelectrode array and the inserter in place.

At step 320, the electrode array is uncompressed, unfurled, deployed orexpanded over the surface of the patient's brain or cortex and at thedesired location or position. In some embodiments, the electrode arrayis unfurled by applying a force, in a direction, to an actuator coupledto the inserter wherein the inserter is a multi-segmented cantilever. Insome embodiments, the electrode array is unfurled by a scissors actionof the actuator or inserter. In some embodiments, the inserter is ahydraulically actuated system built into the electrode array whereinactuation of the hydraulic pressure causes the electrode array tounfurl. In some embodiments, the inserter is embodied as a spring thatis gradually released as the cannula is retracted. In some embodiments,the inserter and/or the grid electrode array comprises a shape-memorymaterial that expands passively causing the electrode array to unfurl.

At step 325, the location or position of the deployed or unfurledelectrode array is verified to ensure that the location or position isindeed the intended, targeted or desired position. At step 330, theinserter is removed and/or released through the burr hole. In someembodiments, the inserter is a hydraulically actuated system wherein theassociated hydraulic pressure is released for removal of the inserter.Finally when desired, at step 335, the electrode array is removed orextracted through the burr hole by teasing it out using at least onepigtail of the electrode array. In embodiments, the flexible substrateof the electrode array will collapse in on itself and exit via theinsertion path and insertion or burr hole.

FIG. 4 illustrates exemplary steps for inserting the electrode systeminto a burr hole, in accordance with some embodiments of the presentspecification. At step 405, a cannula 404, comprising a compressedassembly of an inserter 401 attached to an electrode array 402, isinserted into a burr hole 403 formed in the cranium of a patient. Atstep 410, the cannula 404 is slid back, through the burr hole 403,leaving the compressed assembly of the inserter 401 and the electrodearray 402 in position at a desired or target site on the patient's brainor cortex 407. At step 415, the electrode array 402 is deployed,uncompressed or unfurled by activating an actuator 411 coupled to theinserter 401. Finally, after deployment, at step 420 the inserter 401and the cannula 404 are removed through the burr hole 403, leaving theelectrode array 402 deployed on the patient's brain or cortex 407.

FIG. 5 illustrates exemplary steps for verifying electrode placementusing excitation and field measurements, in accordance with someembodiments of the present specification. For verification, a pluralityof surface electrodes 505 are placed on a patient's scalp 507 such thatthe surface electrodes 505 are over the expected, intended, desired ortarget location where the electrode array 502 is supposed to have beenimplanted and deployed over the surface of the patient's brain or cortex511. In other words, the surface electrodes 505 are located directlyover the electrode array 502 such that they overlap or are mutuallyparallel with the patient's skull in between. Lead wires from theelectrode array 502 are bundled into at least one pigtail 515 and are inelectrical communication with an EEG amplifier 520. The surfaceelectrodes 505 are in electrical communication with an electrical pulsegenerator 510 that causes pulsed electric field to be generated acrossthe plurality of surface electrodes 505.

The pulsed electric field generated across the plurality of surfaceelectrodes 505 is detected as a signal by each implanted grid electrode(of the electrode array 502). The location of each grid electrode iscalculated from such signal using an inverse localization andstatistical comparison to an expected, intended, desired or targetlocation.

FIG. 6A illustrates an assembly of an electrode system 600 in compressedform and housed in a cannula 604 along with a visualization or imagingsystem 630, in accordance with some embodiments of the presentspecification. The electrode system 600 comprises an inserter 601attached to an electrode array 602. The electrode system 600 is incompressed form and contained within the cannula 604, wherein thecannula 604 is stiff enough to be inserted into a desired location anddepth of a patient's skull or cranium. In embodiments, the electrodearray 602 comprises a distal end 602 a and a proximal end 602 b.

In an embodiment, the electrode array 602 is a multi-contact gridelectrode consisting of an array of contacts 603, each of which has alead wire 607 (visible in FIG. 6C). The lead wires 607 are bundled intoone or more pigtails 608 and terminated in a multi-contact connector.Within or alongside the compressed electrode array 602 is a guide wire606. In an alternate configuration, a plunger would follow the leadwires 607 to the proximal end 602 b of the compressed electrode array602. Operationally, after the cannula 604 has been inserted into apatient's skull, it is pulled back, releasing or unfurling thecompressed electrode array 602 using the guide wire 606 or the plungerto keep the electrode array 602 at the desired location and depth. Theelectrode system 600 also includes, in some embodiments, an actuator610.

In some embodiments, as shown in FIG. 6A, the cannula 604 may have acircular cross-section and a straight elongate body. However, inalternate embodiments, as shown in FIG. 6E, the cannula 604 b may havean ovoid or oblong cross-section 605 and may be curved along its lengthto transit a surface of the brain around a curvature of the brain. Insome embodiments, as shown in FIG. 6E, a port 640 in the cannula 604 amay provide compressed gas to generate a brain-cranium gap for insertingthe cannula 604 a and visualizing the insertion and deploymenttrajectory.

In some embodiments, the visualization or imaging system 630 comprises afront-pointing viewing element 632 to visualize and image, based on itsfield of view, insertion and deployment of the electrode array 602 intothe patient's skull and at least one illuminator 634 for illuminating afield of view of the front-pointing viewing element 632. In someembodiments, the front-pointing viewing element 632 is a digital cameracomprising a front-pointing image sensor such as, but not limited to, aCharge Coupled Device (CCD) or a Complementary Metal Oxide Semiconductor(CMOS) image sensor.

In embodiments, the front-pointing viewing element 632 is positioned ata distal tip of an elongated sheath 633. During deployment, theelongated sheath 633 is inserted through a proximal end of the cannula604 such that the front-pointing viewing element 632 lies within,proximal or protrudes a distal end of the cannula 604.

In an embodiment, the front-pointing viewing element 632 is mounted on acircuit board, which supplies it with necessary electrical power, and inan embodiment, generates still images and/or video feeds captured by theimage sensor. In one embodiment, the circuit board is connected to a setof electrical cables (not shown) which are threaded through a channelrunning through the elongated sheath 633. The set of electrical cablesemanate from a proximal end of the sheath 633 for connection to acomputing device and associated display, monitor or screen. In variousembodiments, the computing device is configured with hardware and/orsoftware to receive and process image and/or a video feed acquired bythe front-pointing viewing element 632 and display the image and/orvideo feed on an associated display, monitor or screen. In anembodiment, the front-pointing viewing element 632 has a lens assemblymounted on top of it and provides the necessary optics for receivingimages. In one configuration, the lens assembly includes a plurality oflenses, static or movable, which provide a field of view ranging from 90degrees to 180 degrees.

In some embodiments, the at least one illuminator 634 may include alight-emitting diode (LED), which may be a white light LED, an infraredlight LED, a near infrared light LED, an ultraviolet light LED or anyother LED. In such embodiments, the at least one LED may be coupled tothe same circuit board on which the front-pointing viewing element 632is mounted and positioned proximate the front-pointing viewing element632. In some embodiments, the at least one illuminator 634 may be afiber optic illuminator that transmits light generated from remotesources. In such embodiments, the fiber optic illuminator is insertedthrough the cannula 604 and positioned next to the front-pointingviewing element 632.

During deployment, the at least one illuminator 634 (that is, the LED orthe fiber optic illuminator) together with the front-pointing viewingelement 632 are inserted through the proximal end of the cannula 604 soas to lie proximate or protrude the distal end of the cannula 604. Invarious embodiments, the visualization or imaging system 630 (that is,the front-pointing viewing element 632 and the at least one illuminator634) rests in the cannula 604 during insertion, but may be protrudedbeyond the distal end of the cannula 604 after the cannula 604 ispositioned for deployment—as can be seen in FIG. 6D. In someembodiments, the contents (that is, the visualization or imaging system630 and the electrode system 600) of the cannula 604 are stacked suchthat the visualization or imaging system 630 can be deployed first. Theimaging system 620 once deployed can be moved laterally to provideclearance for the electrode system 600. This allows more room (orclearance) for the electrode system 600 without increasing thecross-sectional size of the cannula 604 while also allowingvisualization of the deployment. Once the electrode system 600 is fullydeployed the front-pointing viewing element 632 fits again through thecannula 604 along with electrode leads or lead wires when the cannula604 is removed.

FIG. 6B is an illustration of the electrode system 600 of FIG. 6A, withthe electrode array 602 in compressed form and removed from the cannula604, in accordance with some embodiments of the present specification.The electrode array 602 is shown in a compressed configuration with thearray of contacts 603 and the lead wires (or electrode leads) 607bundled into at least one pigtail 608. The electrode leads are flexibleand resist breakage when the electrode array 602 is compressed anduncompressed.

In embodiments, the electrode array 602 is attached or coupled to asubstrate 625 having dimensions of 2 cm to 15 in an uncompressed form.The substrate 625 of the electrode array 602 is of sufficient strengthand flexibility so that the array 602 will not fragment during insertionor removal. In some embodiments, if necessary, reinforcing filaments canbe added to the substrate which will effectively distribute the forcesthat come into play during compression and release of the electrodearray 602. In embodiments, the substrate 625 is biocompatible fortemporary implantation and can be sterilized.

In various embodiments, the substrate 625 is made of flexiblebiocompatible material such as silicone rubber and with conductivecontacts as are currently used for grid electrodes such as stainlesssteel, platinum or carbon. The geometry can be variable both in size andshape as is currently supported by invasively placed cortical gridelectrodes. The contacts may also be placed asymmetrically toaccommodate optimal spring positions and to allow ease of placement andremoval. The plurality of electrodes or contacts 603 are distributedacross the substrate 625. Each electrode or contact, of the plurality ofelectrodes or contacts 603, has dimensions of 0.1 mm to 10 mm. In someembodiments, the electrodes or contacts 603 are preferably distributedsuch that there is at least 1 electrode or contact 603 for every 0.1 mm²to 20 mm² of the substrate 625. In various embodiments, the electrodesor contacts 603 are attached or coupled to the substrate 625 using anyattachment mechanism known in the art.

In various embodiments, the electrode array 602 is compressed into aplurality of configurations such as, but not limited to, a firstconfiguration wherein the array 602 is rolled up, a second configurationwherein the array 602 is folded in an accordion-like manner, a thirdconfiguration wherein the array 602 is compressed in a serpentinemanner, a fourth configuration wherein the array 202 is squeezed in atube-like manner or in other ways or configurations that combine or aredifferent from these three exemplary configurations.

Also shown in FIG. 6B is the inserter 601 in compressed form along withthe actuator 610. In various embodiments, the inserter 601 is removablyattached or coupled to the electrode array 602 and/or the substrate 625.In some embodiments, in a compressed state, the substrate 625, incombination with the electrodes/contacts 603, the inserter 601 and thelead wires 607, have dimensions that are less than the substrate 625 andelectrodes/contacts 603 in uncompressed form.

FIG. 6C is an illustration of the electrode system 600 of FIGS. 6A and6B, in uncompressed or expanded form, in accordance with someembodiments of the present specification. As described earlier, the gridelectrode array 602 consists of an array of contacts 603, each of whichhas a lead wire 607. The lead wires 607 are bundled into one or morepigtails 608 and terminated in a multi-contact connector. The pigtails608 pass through the patient's skull and skin, via a burr hole, and themulti-contact connector is external to the patient. In some embodiments,the grid electrode array 602 is fabricated on the substrate 625 which isthin and flexible so as to conform to the surface of the patient's brainwhen applied, and which can be compressed, rolled or folded into atube-like structure for insertion.

An uncompressed or unfurled configuration 601 b of the inserter 601 isalso shown wherein the inserter 601 is embedded/built into, coupled orattached to the flexible substrate 625 that supports the grid electrodearray 602. Unfurling or unfolding of the electrode array 602 requires itto roll across or slide across the surface of the patient's brain. Inaccordance with an aspect of the present specification, the inserter 601is embodied as a spring which is gradually released as the cannula 604(FIG. 6A) is retracted thereby unfurling the electrode array 602.

The inserter 601 embodied as one or more springs, shown in uncompressedform in FIG. 6C, also employs a mechanical actuator 610 to aid unfurlingof the compressed electrode system 600 (FIG. 6B) into an uncompressedstate 600 b (FIG. 6C) for placement on the surface of a patient's brain,in accordance with some embodiments of the present specification. Theactuator 610 is held in place when the cannula 604 (FIG. 6A) isretracted and subsequently released from the spring for removal of theactuator 610.

In some embodiments, referring back to FIG. 6C, a proximal portion 615of the substrate 625 has a tapered shape to facilitate ease of movementthrough the burr hole during retraction of the cannula 604 (FIG. 6A).Additionally, in some embodiments, the electrode contacts 603 as well asthe inserter 610, embodied as one or more springs, are also distributedon the substrate 625 in a tapered configuration to facilitate ease ofmovement of the electrode system 600 through the burr hole duringretraction of the cannula 604 (FIG. 6A).

The spring actuated embodiment expands towards its pre-compressedposition taking the electrode substrate along. As shown in FIG. 6C, theactuator 610 is coupled to a collapsible or expandable spring (orinserter 601).

In some embodiments, the spring is left in place within the substrate625 along with the electrode array 602 upon deployment in the patient'sbrain and provides a collapsing mechanism when the electrode array 602is removed (such as by teasing and tugging at the at least one pigtail608). In alternate embodiments, the spring can be pulled out or releasedfrom the substrate 625 once the electrode array 602 is deployed and itsdesired placement is confirmed.

Referring again to FIG. 6C, in some embodiments, a distribution of theplurality of electrodes or contacts 603 on the substrate 625 may beasymmetrical as locations of the contacts 603 may be required to beshifted to avoid overlap with spring locations.

In various embodiments, the spring (inserter 601) may be configured in aplurality of forms. FIG. 7 shows first, second and third configurations701 a, 701 b, and 701 c of a spring functioning as an inserter, inaccordance with some embodiments of the present specification. In thefirst configuration 701 a, the spring comprises a plurality of separatespring elements 705. In the second configuration 701 b, the springcomprises a plurality of hybrid elements such that at least onesequential or child spring element 710 may be attached or branch offalong a length of at least one preceding or parent spring element 705.

In the third configuration 701 c, the spring is shown incorporatingfirst and second features that enable modulation or adjustment of thespring constant of the spring. In embodiments, the spring constant ofeach spring element 705 may be adjusted for its position along the gridelectrode array. In some embodiments, this is accomplished by adding afirst feature in the form of S-curves 715 to one or more spring elements705. In some embodiments, this is accomplished by incorporating a secondfeature that deals with modifying or changing a geometry 720(comprising, cross-sectional shape and/or size/radius) along a length ofone or more spring elements 705. It should be appreciated, thatattaching at least one child spring element 710 to at least one parentspring element 705, as shown in the second configuration 701 b, alsoenables modulation of the spring constant. In some embodiments, contactsare placed asymmetrically to accommodate optimal spring positions and toallow ease of placement and removal.

While the illustrations of the first, second and third configurations701 a, 701 b, 701 c are of relatively simple spring geometries, itshould be noted that in various alternate embodiments the springgeometries may be more complex to optimize both the unfolding processand to reduce forces and risk of injury. It should be appreciated,however, that in a preferred embodiment, there is at least one firstspring element having a distal end in physical communication with afirst corner or edge of the electrode array (such as the left side) andat least one second spring element having a distal end in physicalcommunication with a second corner or edge of the electrode array (suchas the right side) where 1) the first corner or edge is positionedopposite the second corner or edge, 2) the distal end of the at leastone first spring element is configured to move separate and distinctfrom the distal end of the at least one second spring element,preferably in an opposing direction, and 3) a proximal end of the atleast one first spring element and the at least one second springelement are connected to a common member. It should further beappreciated that additional spring elements may be attached to areas ofthe electrode array proximate the first corner or edge and proximate thesecond corner or edge where each of those additional spring elements areattached, at a proximal end, to the same common member.

In embodiments, the spring elements 705, 710 and features 715, 720 maybe fabricated from materials such as, for example, plastic, metal orcarbon fiber. In embodiments, tips 725 of the spring elements 705, 710are embedded/built into, attached or coupled to the electrode substrate(substrate 625 of FIG. 6C), and the tips 725 themselves are shaped, suchas for example with a ball end or a substantially spherical or bulbousend, to reduce risk of injury to the brain tissue. In some embodiments,the spring is left in place within the substrate along with theelectrode array upon deployment in the patient's brain and provides acollapsing mechanism when the electrode array is removed. In alternateembodiments, the spring can be pulled out or released from the substrateonce the electrode array is deployed and its desired placement isconfirmed.

FIG. 8 is a workflow describing exemplary steps for inserting,expanding, verifying, and extracting the electrode system, in accordancewith some embodiments of the present specification. At step 805, aninsertion, access or burr hole 801 is formed or created in a patient'sskull or cranium 802 at a desired location and of a desired depth so asto enable access to a surface of the patient's brain or cortex 803.

At step 810, a cannula 811 is inserted through the hole 801 with thehelp or guidance of a visualization or imaging system 812 comprising afront-pointing viewing element (such as a digital camera) and at leastone illuminator (such as an LED of a fiber optic illuminator). In someembodiments the cannula 811 may have a circular cross-section and astraight elongate body. However, in alternate embodiments, the cannula811 may have an ovoid or oblong cross-section and may be curved alongits length.

At step 815, in some embodiments, an assembly 816 of an inserterattached to an electrode array is compressed or collapsed and slid orinserted into the access or burr hole 801 through the cannula 811. Inalternate embodiments, a compressed assembly 816 of the inserterattached to the electrode array along with the visualization or imagingsystem 812 is pre-packaged or stacked within the cannula 811 and readyfor deployment. In some embodiments, the inserter is embodied in theform of a collapsible or expandable spring. A plurality of lead wires orelectrode leads emanating from a plurality of electrode contacts of theelectrode array, are bundled together into at least one pigtail 817. Insome embodiments, the cannula 811 includes an orientation mark orindicator (at distal and/or proximal ends of the cannula 811) so that aproper contact surface or side of the electrode array is deployed withcontacts against the brain or cortex 803 when uncompressed. This isadvantageous since the surfaces of the electrode array are notreversible. In alternate embodiments, where the cannula 811 is curvedalong its length, the orientation mark or indicator is not required asthe bearing of the contact surface or side of the electrode array isimplied to be a concave side of the cannula 811. Accordingly, theassembly 816 within the cannula 811 is prepackaged such that the contactsurface or side of the electrode array resides towards the concave sideof the curved cannula 811.

At step 820, the cannula 811 is slid back and partially withdrawnleaving and exposing the assembly 816 of the electrode array and theinserter in place. As the cannula 811 is withdrawn, the compressedassembly 816 expands, unfurls or unfolds due to a recoiling or releasingaction of the spring (inserter) thereby unfurling the electrode arrayover a surface of the patient's brain or cortex 803. In someembodiments, a guide wire 821 is utilized to keep the assembly 816 atthe desired location and depth while the cannula 811 is being retracted,slid back or withdrawn. It should be appreciated that pushing on orholding the guide wire 821 in place, while the cannula 811 is beingretracted, keeps the electrode array and the inserter in place andenables the spring inserter to un-compress or unfurl and spread theelectrode array.

At step 825, the location or position of the deployed or unfurledelectrode array is verified to ensure that the location or position isindeed the intended, targeted or desired position. In embodiments,verification of the deployment is performed visually (using thevisualization or imaging system 812) and/or electrically. For electricalverification, a plurality of surface electrodes 826 (shown in the figureassociated with step 805) are placed on the patient's scalp such thatthe surface electrodes 826 are over the expected, intended, desired ortarget location where the electrode array is supposed to have beenimplanted and deployed over the surface of the patient's brain or cortex803. Lead wires from the electrode array, bundled into at least onepigtail 817, and are in electrical communication with an EEG amplifier.The surface electrodes 826 are in electrical communication with anelectrical pulse generator that causes pulsed electric field to begenerated across the plurality of surface electrodes 826. The pulsedelectric field generated across the plurality of surface electrodes 826is detected as a signal by each implanted grid electrode (of theelectrode array). The location of each grid electrode is calculated fromsuch signal using an inverse localization and statistical comparison toan expected, intended, desired or target location.

At step 830, the cannula 811 is completely withdrawn or retractedleaving the assembly 816 at the target location. As shown, the pigtail817 extends from the hole 801. Finally when desired, at step 835, theassembly 816 is removed or extracted through the hole 801 by teasing itout using the at least one pigtail 817 of the electrode array. Inembodiments, the flexible substrate of the electrode array and theinserter, embodied in the form of the spring, will collapse in on itselfand exit via the insertion path and insertion or burr hole 801.

The above examples are merely illustrative of the many applications ofthe system and method of present specification. Although only a fewembodiments of the present specification have been described herein, itshould be understood that the present specification might be embodied inmany other specific forms without departing from the spirit or scope ofthe specification. Therefore, the present examples and embodiments areto be considered as illustrative and not restrictive, and thespecification may be modified within the scope of the appended claims.

We claim:
 1. A system for deploying an electrode array at a targetlocation within a patient's cranium through a hole formed in thepatient's cranium, the system comprising: a substrate; an array ofelectrodes attached to the substrate; an inserter attached to thesubstrate, wherein the inserter, the substrate, and the array ofelectrodes are configured in a first compressed state and wherein theinserter is configured to expand from the first compressed state to asecond uncompressed state; and a cannula configured to accommodate theinserter, the substrate and the array of electrodes in the firstcompressed state and configured to release the inserter, the substrateand the array of electrodes through the hole and within the patient'scranium at the target location.
 2. The system of claim 1, wherein, inthe first compressed state, the substrate and array of electrodes have awidth that is less than a width of the substrate and array of electrodesin the second uncompressed state.
 3. The system of claim 1, wherein thearray of electrodes comprises a plurality of contacts having associatedlead wires, and wherein each of said lead wires are connected to aterminal on an electrical device.
 4. The system of claim 1, furthercomprising an actuator coupled to the inserter.
 5. The system of claim4, wherein the actuator is configured to be accessible outside thepatient's cranium and further configured such that, when a force isapplied to the actuator, in a first direction, the inserter expands,thereby causing the inserter, the substrate, and the array of electrodesto be in the second uncompressed state.
 6. The system of claim 5,wherein the actuator is configured to be accessible outside thepatient's cranium and further configured such that, when a force isapplied to the actuator, in a second direction, the inserter compresses,thereby causing the inserter, the substrate, and the array of electrodesto be in the first compressed state.
 7. The system of claim 1, whereinthe inserter comprises at least a first spring element and a secondspring element, wherein a distal end of the first spring element isattached to a first edge of the substrate, wherein a distal end of thesecond spring element is attached to a second edge of the substrate, andwherein the first edge opposes the second edge.
 8. The system of claim7, wherein a proximal end of the first spring element and a proximal endof the second spring element are connected to a common member.
 9. Thesystem of claim 1, wherein the inserter comprises a multi-segmentedcantilever coupled to a first and a second actuator.
 10. The system ofclaim 9, wherein the multi-segmented cantilever is configured to expandwhen the first actuator is pulled in a first direction and the secondactuator is pushed in an opposing second direction.
 11. The system ofclaim 1, wherein the substrate has a tapered proximal portion configuredto facilitate ease of extraction of the substrate through the hole. 12.The system of claim 1, wherein the cannula includes a mark to facilitatea proper orientation of a contact surface of the array of electrodesduring release of the inserter, the substrate and the array ofelectrodes.
 13. The system of claim 1, wherein the cannula has an ovoidcross-section and is curved along its length.
 14. The system of claim 1,wherein the cannula includes a port configured to provide compressed gasto generate a brain-cranium gap for inserting the cannula through thehole.
 15. The system of claim 1, wherein the cannula furtheraccommodates a front-pointing viewing element and at least oneilluminator.
 16. A method of deploying an electrode array at a targetlocation within a patient's cranium through a hole formed in thepatient's cranium, the method comprising: obtaining an electrode arraysystem, wherein the electrode array system comprises a cannula having alumen, a substrate, an array of electrodes attached to the substrate,and an inserter attached to the substrate, wherein the substrate, thearray of electrodes, and the inserter are positioned in the lumen in afirst compressed state; inserting the cannula through the hole; slidingthe cannula backwards while positioning the inserter, the substrate, andthe array of electrodes at the target location; and causing theinserter, the substrate and the array of electrodes to transition fromthe first compressed state to a second uncompressed state at the targetlocation.
 17. The method of claim 16, wherein, in the first compressedstate, the substrate and array of electrodes have a width that is lessthan a width of the substrate and the array of electrodes in the seconduncompressed state.
 18. The method of claim 16, wherein the array ofelectrodes comprises a plurality of contacts having associated leadwires and wherein each of said lead wires are connected to a terminal onan electrical device.
 19. The method of claim 16, further comprisingcausing the inserter, the substrate and the array of electrodes totransition from the first compressed state to the second uncompressedstate by moving an actuator attached to the inserter.
 20. The method ofclaim 19, wherein the actuator is configured to be accessible outsidethe patient's cranium and further configured such that, when a force isapplied to the actuator, in a first direction, the inserter expands,thereby causing the inserter, the substrate, and the array of electrodesto be in the second uncompressed state.
 21. The method of claim 19,wherein the actuator is configured to be accessible outside thepatient's cranium and further configured such that, when a force isapplied to the actuator, in a second direction, the inserter compresses,thereby causing the inserter, the substrate, and the array of electrodesto be in the first compressed state.
 22. The method of claim 16, whereinthe inserter comprises at least a first spring element and a secondspring element, wherein a distal end of the first spring element isattached to a first edge of the substrate, wherein a distal end of thesecond spring element is attached to a second edge of the substrate, andwherein the first edge opposes the second edge.
 23. The method of claim22, wherein a proximal end of the first spring element and a proximalend of the second spring element are connected to a common member. 24.The method of claim 16, wherein the inserter comprises a multi-segmentedcantilever coupled to an actuator.
 25. The method of claim 24, whereinthe multi-segmented cantilever is configured to expand when the actuatoris pulled in a first direction and configured to contract when theactuator is pulled in a second direction.
 26. The method of claim 16,further comprising causing the inserter, the substrate and the array ofelectrodes to transition from the second uncompressed state to the firstuncompressed state at the target location.
 27. The method of claim 26,wherein the inserter, the substrate and the array of electrodestransitions from the second uncompressed state to the first uncompressedstate by moving an actuator in physical communication with the inserter.28. The method of claim 26, further comprising removing the cannula andthe inserter through the hole.
 29. The method of claim 26, furthercomprising extracting the array of electrodes through the hole.
 30. Themethod of claim 16, further comprising verifying a physical position ofat least one of the inserter, the substrate or the array of electrodeswithin the patient's cranium.
 31. A method of deploying an electrodearray at a target location onto a patient's cortex through a burr holeformed on the patient's cranium, the method comprising: inserting acannula through said burr hole, said cannula accommodating an inserterand an array of electrodes, wherein said inserter and array ofelectrodes are in a first state; sliding the cannula backwards whilepositioning said inserter and array of electrodes in said first state atsaid target location; causing said array of electrodes to be in a secondstate at said target location; and verifying said positioning of saidinserter and array of electrodes at said target location.
 32. The methodof claim 31, further comprising removing the cannula and the inserterthrough the burr hole.
 33. The method of claim 32, further comprisingextracting the array of electrodes through the burr hole.
 34. The methodof claim 31, wherein, in said first state, the inserter and array ofelectrodes are compressed.
 35. The method of claim 31, wherein, in saidsecond state, the array of electrodes is expanded.